you can try the low imp position Med or High. It is a reference only . Please use your ear to determine which setting is good for your ear
The tubes that I am using are just to burn in the amp. After the burn in period, I will put in the KT170s that I bought from you. I have lot of Mullard 12AU7As to pair them with. I will let you know how it goes. The last A in the 12au7a means that the anodes have been plated therefore eliminating the start up flash.
My TU-8850 is picking up RF from my computer and/or monitor. They're only a couple of feet away on my desktop. I didn't have this problem with my TU-8600 or TU-8900 both in the same location. Any ideas on how to mitigate the RF? I can conceivably move the amp, but I don't really want to. It's set up for my convenience.
Do not judge a book by its cover. This is a Xf4. Mullard labeled as a National Electronics, who was an tube distributor up until the end of the 80s. I bought them for 100$ a sleeve. I still have one sleeve left. In the 8850 the mids are to die for. These are quiet tubes. The image is almost holographic. I am really having fun tube rolling with this amp
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If you look at Thread#58 from TU-8550 Pre-Amp, I had the same problem with RF with right channel interference. It was the PC/Router WiFi and I added Copper sheet. I was not going to re-locate the PC or Router.
https://www.diyaudio.com/community/threads/elekit-tu-8550-pre-amplifier.385135/page-3
I moved the 8550 to another room and the RF interference went away (as I knew it would). Now I've confirmed some instability at higher volumes. It acts like the tubes are microphonic. I swapped some KT-88s and so far the distortion has not reappeared. I'll be testing some more, but for now it seems like the KT-170s are no bueno for this amp. I'm sure Victor has tested these extensively so I'm not sure if it's my setup or the tubes I got. We'll see.